Computerized sewing is a well established technology, now in use for more than a decade. A sewing program is prepared mathematically in advance of sewing operations, based on a theoretical part to be sewn. This program is provided to the computerized sewing machine which sews the actual part in accordance with the program.
In computer controlled sewing systems it is known to add edge following capability by means of visual feedback using video cameras mounted on the sewing systems. This is disclosed in U.S. Pat. Nos. 4,784,071, 4,834,008 and 4,932,343, and enables modification of a sewing path, described by a theoretical sewing program, according to the actual position and shape of the sewn part and its edges.
The addition of vision sense to the computer controlled sewing systems enhanced dramatically the accuracy of the sewing process as compared to the results from conventional computerized stitchers. However, a process of designing or writing the sewing program in advance is still required. This process, although it is done today by advanced Computer Aided Design (CAD) means, still takes considerable time and effort and a skilled CAD operator is needed. Occasionally, the CAD system is located far away from the sewing system and the logistics and additional time involved in transferring the sewing program from the CAD system to the sewing system can lead to increased production costs.
The problem is more difficult when modifications are required in the sewing program. An iterative process of returning to the CAD system and changing the program and then testing it again on the computerized stitcher could prove to be a lengthy process indeed.
In addition, with conventional computerized stitchers, a special pallet is required for each shape of piece to be sewn. This pallet is generally formed of aluminum or PVC and is designed to grasp the part to be sewn during the sewing process and includes apertures for passage of the needle along each required seam. Producing this pallet is an expensive and time consuming process.